Convection enhanced delivery, or CED, is a local delivery technique for the distribution of infused compounds. CED uses bulk flow to deliver small or large molecules into targeted sites, for example in the brain, through stereotactically positioned catheters. Bypassing the blood brain barrier, CED can expose tumors and other target tissues to therapeutic agents, minimizing systemic exposure so as to result in fewer systemic side effects.
A number of factors are believed to significantly impact the success of local drug delivery via CED. The first such factor is backflow along the outer surface of the infusion catheter, which typically occurs with larger catheter diameters and higher infusion rates. The second such factor is the intrusion of air and pressure peaks that can arise from disconnecting and reconnecting the system after the catheter has been placed. The third such factor is the anatomic accuracy of the catheter placement and the prevention of leakage into the cerebrospinal fluid compartment of the infusate.